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Spark Plug Issue
- Thread starter steveg
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Hello Steve, I don't have an answer on this but I have a picture of mine which doen't explain anything and only creates more questions. My 2 & 3 were definately darker but they were not oil fouled. They were just a dry darker colour. The number 3 was the worse. I did nothing but switch the number 3 and 6 spark plugs. In the pic they are numbered from left to right, 6 to 1. After the switch and a good 1- 1/2 hour run I pulled the plugs and the pic shows what they look like. Doesn't make any sense to me but the pic shows they all look pretty good. And the one in number 6 position which was number 3 is starting to lighten up a little. I don't have a clue except I would say go back to basics. Give it the best tune up possible.
I'm not an expert but IMO I would say that according to what can be seen in your pic, your numbers 2 & 3 seem to be getting oil. It's a sticky wetness that doesn't dry off very quickly. I would say that your 6, 5 & 4 are lean. The reason I say that is because the #5 is very clean with hardly any sign of contamination. Without the contamination it is showing the true setting of the rear carb which is fairly white. I would be concerned that the carb is too lean. I think your front carb is set about right but the oil infiltration in cylinders 2 & 3 are fouling things up. A hotter plug may very well clean up the 2 & 3 sufficiently to not cause any more issues, BUT!, you should richen the rear carb or the hotter plugs are going to be too hot for the exiting mix in cylinder 4,5,&6.
Well I guess I walked into that as a matter of personal interpretation. I may be totally wrong on this assessment. Please forgive my bluntness. Dave.
I'm not an expert but IMO I would say that according to what can be seen in your pic, your numbers 2 & 3 seem to be getting oil. It's a sticky wetness that doesn't dry off very quickly. I would say that your 6, 5 & 4 are lean. The reason I say that is because the #5 is very clean with hardly any sign of contamination. Without the contamination it is showing the true setting of the rear carb which is fairly white. I would be concerned that the carb is too lean. I think your front carb is set about right but the oil infiltration in cylinders 2 & 3 are fouling things up. A hotter plug may very well clean up the 2 & 3 sufficiently to not cause any more issues, BUT!, you should richen the rear carb or the hotter plugs are going to be too hot for the exiting mix in cylinder 4,5,&6.
Well I guess I walked into that as a matter of personal interpretation. I may be totally wrong on this assessment. Please forgive my bluntness. Dave.
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Dave - no problem with bluntness - my sentiments exactly. I believe it is oil, as it will still be shiny after a long enough period that gas would evaporate - indeed indefinitely.
Today after a 20 mile drive on brand-new hotter BP5ES plugs gapped to .025", 2 & 3 had an oil sheen and the others looked lean as you note above. I replaced the BP6ES colder plugs back into 1, 4, 5 and 6, leaving the 5s in 2 & 3. I will richen the rear carb up slightly. The car backfires a little going downhill against compression -- in my past experience if I don't have an air leak between the headers and flex pipes, this means I'm a little lean.
Today after a 20 mile drive on brand-new hotter BP5ES plugs gapped to .025", 2 & 3 had an oil sheen and the others looked lean as you note above. I replaced the BP6ES colder plugs back into 1, 4, 5 and 6, leaving the 5s in 2 & 3. I will richen the rear carb up slightly. The car backfires a little going downhill against compression -- in my past experience if I don't have an air leak between the headers and flex pipes, this means I'm a little lean.
OP
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Andrea, do you mean the 4th cylinder? BP5 are already on #2 & 3. This is the first time #4 has been a little sooty - usually it has been same as 5 & 6.
Have used the colortunes on cylinders 2 and 5 - may do that again, but the front carb is almost adjusted.
OP
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Will try to remember to do this and report back on the weekend. I've done it in the recent past with mixed results. Also mixed results with the colortunes.
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andrea
Jedi Knight
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Yes Steve I was wrong and confused by the photos- I am just returned from a trip of more than 1000 Km in TUSCANY with NO trouble-I will see my SPARKS condition
as soon possible I shot a photo (my car are normally rich)
tahoe healey
Yoda
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I'm just curious as to what the plugs are gaped at. I tend to gap mine at 24 but some of you go as high as 26. I believe the more open the gap, the hotter the spark???
OP
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Mine are all gapped at .025".
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Mine are gapped at 0.030", but I have a Crane system with an older Lucas Sports coil.
The gap should be 0.025" unless the spark voltage is raised.
The gap should be 0.025" unless the spark voltage is raised.
andrea
Jedi Knight
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Today I find the time to control my AH after a long trip in TUSCANY --https://picasaweb.google.com/112770819864514987162/TUSCANYRAYD2015
Here My SPARKS LFR5B (machined) photos
https://picasaweb.google.com/112770819864514987162/AHWORKSAndUPGRADEProject#6194060279260175122
My front carb need some attention- and the rear is to lean? opinion agreed
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The rear ones are ok, the front carb is too rich.
OP
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